We considered the trace starting from the beginning of the horizontal line and ending at the determined Romidepsin end time. We measured the amplitude from the horizontal line to the peak of the interpolated trace, measured the width of the interpolated trace at the Vm halfway between the horizontal line and the peak (crossing any transient dips between the outermost limits), and computed the product of this amplitude and width. For each cell, we set three thresholds for amplitude, width, and amplitude × width, and classified those events that satisfied all three thresholds to be CSs. The thresholds were ∼15 mV, ∼25 ms,

and ∼15 × 25 mV × ms, respectively, adjusted manually based on visual inspection of the resulting classification. A few events classified as CSs were rejected upon manual inspection. For determining the location at which a CS occurred, we set the time of occurrence to be that of the peak of the first AP in the CS. The Vm reached by the slow, large depolarization of each CS was determined as follows. Intervals from the minimum Vm between 3 ms before the peak and the peak, to the minimum Vm between the peak and 5 ms after the peak of each AP www.selleckchem.com/products/Staurosporine.html or spikelet were removed from

the CS’s Vm trace, linear interpolation was applied across the resulting gaps, the interpolated trace was low-pass-filtered with high cutoff 20 Hz, then the peak was taken from this smoothed trace. Figure S2A shows the distribution of these values for all CSs from all place and silent cells (mean ± SD = −24.2 ± 4.4 mV). The mean plateau level of all CSs from a given cell was consistent across place, silent, active, and nonactive

cells (mean ± SD = −24.1 ± 2.8 mV) (only one silent cell and no additional nonactive cells had CSs). This mean plateau level and the baseline Vm were uncorrelated (ρ = −0.12; p = 0.76; regression line: mean CS plateau level = −0.078 × baseline Vm − 29.0 mV), and the mean plateau level and AP threshold were uncorrelated (ρ = 0.41; p = 0.27; mean CS plateau level = 0.26 × AP threshold − 10.4 mV) across cells. Immediately upon breaking into the neuron and achieving the whole-cell recording configuration, while the animal was anesthetized, we injected all a series of depolarizing current steps. For each step, the current started at 0 nA, lasted for 300 ms, then returned to zero. The first depolarizing step was 0.1 or 0.2 nA and was increased in increments of 0.1 or 0.2 nA, respectively, for successive steps. The firing pattern of the first step that evoked ≥5 APs was used to determine the propensity to burst and is shown for each cell in Figure 5. The degree of bursting was defined as the fraction of all APs in the firing pattern that occurred in bursts of ≥2 APs with ISIs ≤10 ms.